Impact of rainwater catchment systems on stormwater discharge in two neighborhoods in Potash Brook watershed Impact of rainwater catchment systems on stormwater.

Impact of rainwater catchment Impact of rainwater catchment systems on stormwater discharge in systems on stormwater discharge in two neighborhoods in Potash Brook two neighborhoods in Potash Brook

watershedwatershed

MarySutton Carruthers

Kristen Hendrick

Emily Schelley

Kyle Velvis

Problem StatementProblem Statement

Currently there is no assessment of the potential for decreasing discharge rates in Butler Farm neighborhood or in the Airport neighborhood

An assessment could provide scientific justification for management decisions dealing with water quality

Background/JustificationBackground/Justification

High discharge rates are associated with increased erosion, sedimentation and pollutant loading into streams

Can cause changes in geomorphology and adversely affect benthic invertebrates

Types of Catchment SystemsTypes of Catchment Systems

Rain Barrels-Large container (50-80

gallons) placed at downspout to collect rooftop runoff

-Water is saved for use during dry periods

Types of Catchment Systems Types of Catchment Systems

Rain Gardens-Shallow landscaped

depression positioned to capture stormwater runoff

-planted with native, water tolerant plants

-reduction in fertilizer use

-additional habitat

Site DescriptionSite Description

Neighborhood A – Neighborhood A – AirportAirport

101 houses occupying ~36 acres of land

Soil hydrogroup A Adams and

Windsor loamy sand soil classes most prominent

Excessively drained rapid permeability

Soil class descriptions taken from USDA-NRCS

Neighborhood D – Neighborhood D – Butler FarmsButler Farms

248 houses sitting on ~135 acres

Soil hydrogroup D Vergennes clay and

Farmington silty loam most prominent soil classes

Moderate to slow permeability, moderately well drained

Soil class descriptions taken from USDA-NRCS

Model Inputs/AssumptionsModel Inputs/Assumptions

Altered drainage patternsDefault storm data used from NRCS Percent impervious based on CWP dataMitigation effort represents 8% reduction in

effective impervious areaLongest flow path determination

FindingsFindings

Neighborhood A Peak Flows

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

1 yr 5 yr 50 yr 1 yr 5 yr 50 yr

Current Mitigated

Event

Pe

ak F

low

(m

m/h

r)

FindingsFindingsNeghborhood D Peak Flows

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

1 yr 5 yr 50 yr 1 yr 5 yr 50 yr

Current Mitigated

Event

Pe

ak F

low

(m

m/h

r)

FindingsFindings

    % reduction in peak flow

Neighborhood A 50 yr 58.3

Neighborhood D 1 yr 18.2

  5 yr 13.1

  50 yr 9.6

RecommendationsRecommendations

Airport neighborhood:

– Mitigation efforts useful…howeverCurrent situation does NOT show high flow

because of PERMEABLE soils

– No catchment systems recommended

RecommendationsRecommendations

Butler Farm

– Current situation shows high flows… howeverMitigation NOT useful because of

IMPERMEABLE soils

– Alternate catchment systems, such as detention ponds should be assessed

Questions/Comments/PraiseQuestions/Comments/Praise

Thanks to Breck, Erica and our fellow Environmental Scientists